干旱胁迫对桢楠幼树渗透调节与活性氧代谢的影响及施氮的缓解效应

doi:10.17521/cjpe.2017.0225

摘要/Abstract

摘要：

以二年生桢楠(Phoebe zhennan)幼树为研究对象, 采用盆栽控水的方法, 探讨了桢楠幼树在干旱胁迫下渗透调节和活性氧代谢的变化, 以及施氮对桢楠幼树应对干旱胁迫能力的影响。试验先将土壤含水量调整到4个梯度(田间持水量的80% (80% FC)、50% FC、30% FC和15% FC), 1周后测定受胁迫植株的相关生理指标, 之后进行3个水平的施氮处理(对照N0, 中氮MN, 高氮HN, 各施氮量分4次(即干旱梯度形成后第7、14、21和28天)分别施入)。在施氮结束后30天(即开始施肥处理后51天)再次测定各项生理指标。结果表明: 1)干旱处理7天后, 桢楠叶片中游离脯氨酸(Pro)和可溶性糖(SS)含量均随胁迫强度增大而显著增加, 重度干旱(15% FC)下的Pro含量增加尤为明显, 可溶性蛋白(SP)含量则呈先增加后降低的趋势。施氮后, 各种土壤水分状态下的Pro含量进一步增加。水分充足和轻度干旱MN水平下, SS含量也增加, 而在中度和重度干旱下的SS含量显著降低, HN水平各干旱状态下SS含量变化均不显著。施氮结束后30天时, 80% FC和50% FC下的SP含量表现为施氮组低于对照组, 而30% FC和15% FC下则相反。2)施氮前随着干旱胁迫的增强, 桢楠幼树叶片中过氧化氢(H₂O₂)含量、超氧化物歧化酶(SOD)活性、过氧化氢酶(CAT)活性显著上升, 而过氧化物酶(POD)活性呈先上升后下降的趋势。施氮后, H₂O₂含量总体上表现为减少趋势, 且MN水平下降幅度最大, HN水平反而不利于降低H₂O₂的含量。3种酶活性的变化则因干旱程度和施氮水平的不同而呈现出不同的变化趋势。3)施氮前随着干旱胁迫的增强, 叶片丙二醛(MDA)含量呈显著上升趋势, 相对电导率(REC)先显著下降后显著上升; 施氮后, 除重度干旱胁迫外, 其他各干旱处理植株的MDA含量都表现为在MN水平下有所下降, 而在HN水平下有所回升, 但在重度干旱时, 无论是MN或HN处理, MDA含量均呈上升趋势, 表明在重度干旱胁迫下, 难以通过施氮的方式缓解干旱胁迫产生的伤害。4)双因素方差分析显示, 施氮与干旱胁迫间具有极显著的交互效应。以上结果表明: 施一定量的氮肥有利于缓解桢楠幼树受到的干旱胁迫, 以年施氮量计, 施中氮(N元素质量为1.35 g·株 ^-1)对除重度干旱外的干旱胁迫具有一定的缓解作用, 但施高氮(N元素质量为2.70 g·株 ^-1)时反而会对植株造成不利影响。

关键词: 桢楠, 幼树, 干旱胁迫, 渗透调节, 活性氧, 施氮

Abstract:

Aims Two-year-old seedlings of Phoebe zhennan were used in this study to explore the responses of osmotic adjustment and active oxygen metabolism to drought stress and the mitigation effect of nitrogen application.

Methods The soil water content was firstly adjusted to four treatment levels, i.e. 80% of field water holding capacity (80% FC), 50% FC, 30% FC and 15% FC, respectively. The physiological variables of plants were measured after one week, and then three nitrogen application rates, control (N0), medium nitrogen (MN) and high nitrogen (HN) were performed at an interval of 7 days for four times (7 d, 14 d, 21 d and 28 d, respectively). The same physiological variables were determined again one month after the accomplishment of nitrogen application.

Important findings 1) The free proline (Pro) and soluble sugar (SS) contents in the leaves increased significantly with the aggravation of drought stress after 7 days of drought, but the content of soluble protein (SP) was firstly increased and then declined. The increase of Pro content was especially obvious under severe drought (15% FC). After nitrogen application, the content of Pro raise further, but the values varied in drought treatment. The SS contents under sufficient water supply (80% FC) and mild drought (50% FC) were decreased by MN, but it did not change significantly when supplied with HN despite the soil water content. After nitrogen application, the SP contents under 80% FC and 50% FC were lower than those of no exogenous N, while they were opposite response under 30% FC and 15% FC. 2) Before nitrogen application, with the aggravation of drought stress, the hydrogen peroxide (H₂O₂) content, superoxide dismutase (SOD) activity, catalase (CAT) activity increased significantly, and the peroxidase (POD) activity showed an up-down trend. After nitrogen application, the content of H₂O₂ was generally deceased at each water condition, with the maximum decrease at MN, while the HN treatment was not conducive to reduce the content of H₂O₂. The activities of three kinds of enzymes responded differently to the severity of drought and the level of nitrogen application. 3) Before nitrogen application, the content of malondialdehyde (MDA) in leaves increased significantly when the soil water content declined to and below 50% FC. The relative electrical conductivity (REC) was decreased at first, and followed by significant increase. Except severe drought (15% FC) stress, the MDA content showed a decreasing trend at MN, but a rebound at HN. As regards severe drought stress, however, the content of MDA increased at both MN and HN, indicating that nitrogen application is not a good choice to alleviate the damage caused by severe drought stress. 4)Two-factor ANOVA revealed an obvious interaction between nitrogen application and drought stress. In conclusion, a proper amount of nitrogen (1.35 g·a ^-1 for each sapling) could somewhat alleviate drought stress no severer than 15% FC on seedlings of Phoebe zhennan, but excessive nitrogen at rate of or more than 2.70 g·a ^-1 per sapling is not recommended.

Key words: Phoebe zhennan, seedlings, drought stress, osmotic adjustment, reactive oxygen, nitrogen application

王曦,胡红玲,胡庭兴,张城浩,王鑫,刘丹. 干旱胁迫对桢楠幼树渗透调节与活性氧代谢的影响及施氮的缓解效应. 植物生态学报, 2018, 42(2): 240-251. DOI: 10.17521/cjpe.2017.0225

Xi WANG,Hong-Ling HU,Ting-Xing HU,Cheng-Hao ZHANG,Xin WANG,Dan LIU. Effects of drought stress on the osmotic adjustment and active oxygen metabolism of Phoebe zhennan seedlings and its alleviation by nitrogen application. Chinese Journal of Plant Ecology, 2018, 42(2): 240-251. DOI: 10.17521/cjpe.2017.0225

导出引用管理器 EndNote|Ris|BibTeX

链接本文: https://www.plant-ecology.com/CN/10.17521/cjpe.2017.0225

https://www.plant-ecology.com/CN/Y2018/V42/I2/240

图/表 16

参考文献 50

[1]	Aebi H ( 1984). Catalase in vitro. Methods in Enzymology, 105, 121-126. DOI URL
[2]	Blackman CJ, Brodribb TJ, Jordan GJ ( 2010). Leaf hydraulics and drought stress: Response, recovery and survivorship in four woody temperate plant species. Plant, Cell & Environment, 32, 1584-1595.
[3]	Breshears DD, Cobb NS, Rich PM, Price KP, Allen CD, Balice RG, Romme WH, Kastens JH, Floyd ML, Belnap J, Anderson JJ, Myers OB, Meyer CW ( 2005). Regional vegetation die-off in response to global-change-type drought. Proceedings of the National Academy of Sciences of the United States of America, 102, 15144-15148. DOI URL PMID
[4]	Caprioli M, Krabbe KA, Melone G, Raml?v H, Ricci C, Santo N ( 2004). Trehalose in desiccated rotifers: A comparison between a bdelloid and a monogonont species. Comparative Biochemistry and Physiology-Part A: Molecular & Integrative Physiology, 139, 527-532. DOI URL PMID
[5]	Chen LS, Liu XH ( 2001). Effects of water stress on cell wall H +-ATPase activity in leaves of Litchi chinensis Stone. with different drought-resistance. Journal of Tropical and Subtropical Botany, 9(2), 149-153.
	[ 陈立松, 刘星辉 ( 2001). 水分胁迫对抗旱性不同的荔枝叶片细胞壁H +-ATPase活性的影响 . 热带亚热带植物学报, 9(2), 149-153.]
[6]	Chen SY ( 1991). Injury of membrane lipid peroxidation to plant cell. Plant Physiology Communication, 27(2), 84-90.
	[ 陈少裕 ( 1991). 膜脂过氧化对植物细胞的伤害. 植物生理学通讯, 27(2), 84-90.]
[7]	Dai YC, Xu KY, Ma K, Zhang Y, Xia GH ( 2015). Physiological responses of the rare and endangered Ardisia violaceaMyrsinaceae) seedlings to progressive drought stress. Acta Ecologica Sinica, 35, 2954-2959. DOI URL
	[ 代英超, 徐奎源, 马凯, 张云, 夏国华 ( 2015). 珍稀濒危植物堇叶紫金牛对持续干旱的生理响应. 生态学报, 35, 2954-2959.] DOI URL
[8]	Dashek WV, Erickson SS ( 1981). Isolation, assay, biosynthesis, metabolism, uptake and cranslocation and function of proline in plant cells and tissues. Botanical Review, 47, 349-385. DOI URL
[9]	Delhaize E, Ryan PR ( 1995). Aluminum toxicity and tolerance in plants. Plant Physiology, 107, 315-321. DOI URL PMID
[10]	Fang WP ( 1981). Flora of Sichuan. Sichuan People’s Publishing House, Chengdu.
	[ 方文培 ( 1981). 四川植物志. 四川人民出版社, 成都.]
[11]	Fridorich I ( 1975). Superoxide dismutase. Annual Review of Biochemistry, 44, 147-159. DOI URL
[12]	Gao JF ( 2006). Experimental Guidance for Plant Physiology. Higher Education Press,Beijing. 211.
	[ 高俊凤 ( 2006). 植物生理学实验指导. 高等教育出版社, 北京. 211.]
[13]	Giannopolitis CN, Ries SK ( 1977). Superoxide dismutases: I. Occurrence in higher plants. Plant Physiology, 59, 309-314. DOI URL PMID
[14]	Hanson AD, Nelsen CE, Pedersen AR, Everson EH ( 1979). Capacity for proline accumulation during water stress in barley and its implications for breeding for drought resistance. Crop Science, 19, 489-493. DOI URL
[15]	Hasio TC ( 1973). Water and Plant Life. Academic Press, New York. 281-303.
[16]	Hason AD ( 1980). Interpreting the metabolic response of plants to water stress. Hortscience, 15, 623-629.
[17]	Heikkala JJ, Papp JTE, Schultz GA, Bewley JD ( 1984). Induction of heat shock protein messenger RNA in maize mesocotyls by water stress, abscisci acid and wounding. Plant Physiology, 76, 270-274. DOI URL PMID
[18]	Hisao TC ( 1973). Plants response to water stress. Annual Review of Plant Physiology, 24, 519-570. DOI URL
[19]	Hulbert C, Funkhouder EA, Soltes EJ, Newton RJ ( 1988). Inhibition of protein synthesis in loblolly pine hypocotyls by mannitol-induced water stress. Tree Physiology, 4, 19-26. DOI URL PMID
[20]	Kocheva KV, Georgiev GI, Kochev VK ( 2014). An improvement of the diffusion model for assessment of drought stress in plant tissues. Physiologia Plantarum, 150, 88-94. DOI URL PMID
[21]	Kuhns MR, Gjerstad DH ( 1988). Photosynthate allocation in loblolly pine (Pinus taeda) seedlings as affected by moisture stress. Canadian Journal of Forest Research, 18, 285-291.
[22]	Lawlor DW, Cornic G ( 2002). Photosynthetic carbon assimilation and associated metabolism in relation to water deficits in higher plants. Plant, Cell and Environment, 25, 275-294. DOI URL PMID
[23]	Li HS ( 2012). Modern Plant Physiology. Higher Education Press,Beijing.
	[ 李合生 ( 2012). 现代植物生理学. 高等教育出版社, 北京.]
[24]	Li HS, Shun Q, Zhao SJ, Zhang WH ( 2000). Principles and Techniques of Plant Physiology and Biochemistry Experiments. Higher Education Press,Beijing. 164- 165, 258-260.
	[ 李合生, 孙群, 赵世杰, 章文华 ( 2000). 植物生理生化实验原理和技术. 高等教育出版社, 北京. 164-165, 258-260.]
[25]	Li J ( 2015). Effects of drought stress on soluble proteins of Hordeum vulgare Linn. seedlings. Jiangsu Agricultural Sciences, 43(12), 124-126. DOI URL
	[ 李洁 ( 2015). 干旱胁迫对青稞幼苗可溶性蛋白的影响. 江苏农业科学, 43(12), 124-126.] DOI URL
[26]	Li J, Huang LH, Chen X ( 2015). Physiological response of two Rhododendron simsii seedlings to drought stress and drought resistance evaluation. Southwest China Journal of Agricultural Sciences, 28, 1067-1073. DOI URL
	[ 李娟, 黄丽华, 陈训 ( 2015). 2种杜鹃对干旱胁迫的生理响应及抗旱性评价. 西南农业学报, 28, 1067-1073.] DOI URL
[27]	Li N ( 2014). Physiological and Ecological Response of Larix gmelinii Seedlings under Soil Drought Stress and Different Nitrogen Levels. Master degree dissertation, Northeast Forestry University,Harbin.
	[ 李娜 ( 2014). 落叶松幼苗对干旱胁迫及氮添加的生理生态响应. 硕士学位论文, 东北林业大学, 哈尔滨.]
[28]	Li Q ( 2013). Physiological Responds and Adaptation of Miscanthus sacchariflorus and Miscanthus sinensis to Drought Stress. PhD dissertation, Northeast Forestry University, Harbin. 45.
	[ 李强 ( 2013). 荻和芒对干旱胁迫的生理响应和适应性. 博士学位论文, 东北林业大学, 哈尔滨. 45.]
[29]	Li YJ, Li J, Xu P, He HW ( 2014). Physiological responses of Lycium ruthenicum Murr. seedlings to drought stress. Arid Zone Research, 31, 756-762.
	[ 李永洁, 李进, 徐萍, 何宏伟 ( 2014). 黑果枸杞幼苗对干旱胁迫的生理响应. 干旱区研究, 31, 756-762.]
[30]	Liu J, Lü B, Xu LL ( 2000). An improved method for the determination of hydrogen peroxide in leaves. Progress in Biophysics, 27, 548-551. DOI URL
	[ 刘俊, 吕波, 徐朗莱 ( 2000). 植物叶片中过氧化氢含量测定方法的改进. 生物化学与生物物理进展, 27, 548-551.] DOI URL
[31]	Liu S, He Q, Li JY, Su Y, Wu JW ( 2016). Physiological responses of the limestone endemic plant Triadica rotundifolia seedlings to drought stress. Journal of South China Agricultural University, 37(2), 96-100.
	[ 刘珊, 何茜, 李吉跃, 苏艳, 吴俊文 ( 2016). 石漠化树种圆叶乌桕对干旱胁迫的生理响应. 华南农业大学学报, 37(2), 96-100.]
[32]	Liu ZQ, Zhang SC ( 1994). Plant Resistance Physiology. China Agriculture Press, . Beijing 84-123.
	[ 刘祖琪, 张石诚 ( 1994). 植物抗性生理学. 中国农业出版社, 北京. 84-123.]
[33]	Lü EE, Zhou XR, Zhou ZY, Zhao GQ ( 2016). Physiological responses of the desert shrub Hedysarum mongolicum to drought stress. Acta Prataculturae Sinica, 25(6), 42-50. DOI URL
	[ 吕娥娥, 周向睿, 周志宇, 赵桂琴 ( 2016). 荒漠灌木蒙古岩黄芪对干旱胁迫的生理响应. 草业学报, 25(6), 42-50.] DOI URL
[34]	Misra A, Tyler G ( 1999). Influence of soil moisture on soil solution chemistry and concentrations of minerals in the calcicoles Phleum phleoides and Veronica spicata grown on a limestone soil. Annals of Botany, 84, 401-410.
[35]	Pan RZ ( 2012). Plant Physiology. Higher Education Press, Beijing.
	[ 潘瑞炽 ( 2012). 植物生理学. 高等教育出版社, 北京.]
[36]	Patakas A, Nikolaou N, Zioziou E, Radoglou K, Noitsakis B ( 2002). The role of organic solute and ion accumulation in osmotic adjustment in drought-stressed grapevines. Plant Science, 163, 361-367. DOI URL
[37]	Sun M, An Y, Wang Q, Pan L ( 2010). Effect of water stress and nitrogen application on morphological and physiological character of Zoysia japonica cv. Shanghai. Pratacultural Science, 27(9), 57-63.
	[ 孙明, 安渊, 王齐, 潘磊 ( 2010). 干旱胁迫和施氮对结缕草种群特征和生理特性的影响. 草业科学, 27(9), 57-63.]
[38]	Taiz L, Zeiger E ( 2010). Plant Physiology. Sinauer Associates, North Miami Beach, USA.
[39]	Taylor CB ( 1996). Proline and water deficit: Ups, downs, ins and outs. Plant Cell, 8, 1221-1224. DOI URL
[40]	Tyree MT, Zimmermann MH ( 2002). Xylem Structure and the Ascent of Sap. Springer, Berlin.
[41]	Wright IJ, Reich PB, Westoby M, Ackerly DD, Baruch Z, & Bongers F, Cavender-Bares J, Chapin T, Cornelissen JHC, Diemer M, Flexas J, Garnier E, Groom PK, Gulias J, Hikosaka K, Lamont BB, Lee T, Lee W, Lusk C, Midgley JJ, Navas ML, Niinemets ü, Oleksyn J, Osada N, Poorter H, Poot P, Prior L, Pyankov VI, Roumet C, Thomas SC, Tjoelker MG, Veneklaas EJ, Villar R ( 2004). The worldwide leaf economics spectrum. Nature, 428, 821-827. DOI URL
[42]	Wu XH, Zheng GP ( 1995). Effect of the moisture content coercive on morphological and physiological process of crops. Journal of Qiqihar Teachers’ College (Natural Science), 15(3), 37-40.
	[ 吴旭红, 郑桂萍 ( 1995). 水分胁迫对作物形态和生理过程的影响. 齐齐哈尔师范学院学报(自然科学版), 15(3), 37-40.]
[43]	Xiong QE ( 2003). Experimental Course in Plant Physiology. Sichuan Science and Technology Publishing House, Chengdu.72-73, 85-86, 126-127.
	[ 熊庆娥 ( 2003). 植物生理学实验教程. 四川科学技术出版社, 成都. 72-73, 85-86, 126-127.]
[44]	Yan H, Jia LH, Wang GX ( 2002). Research progress of plant water stress inducible proteins. Chemistry of Life, 22, 165-168. DOI URL
	(in Chinese with English abstract) [ 颜华, 贾良辉, 王根轩 ( 2002). 植物水分胁迫诱导蛋白的研究进展 . 生命的化学, 22, 165-168.] DOI URL
[45]	Yang CB, Yao JX, Li SW, Ni HQ, Liu YQ, Zhang YH, Li JH ( 2016). Growth and physiological responses to drought stress and comprehensive evaluation on drought tolerance in Leuce clones at nursery stage. Journal of Beijing Forestry University, 38(5), 58-66.
	[ 杨传宝, 姚俊修, 李善文, 倪惠菁, 刘元铅, 张有慧, 李际红 ( 2016). 白杨派无性系苗期对干旱胁迫的生长生理响应及抗旱性综合评价. 北京林业大学学报, 38(5), 58-66.]
[46]	Yang DG, Liu YX, Zhang Q, Jiang ZZ, Song BG ( 2015). Progress on crops osmotic adjustment and genetic engineering of osmotic stress resistance. Crops, ( 1), 6-13.
	[ 杨德光, 刘永玺, 张倩, 姜籽竹, 宋北光 ( 2015). 作物渗透调节及抗渗透胁迫基因工程研究进展. 作物杂志, ( 1), 6-13.]
[47]	Zhang JX, Kirkham MB ( 1994). Drought-stress-induced changes in activities of superoxide dismutase, catalase, and peroxidase in wheat species. Plant Cell Physiology, 35, 785-791. DOI URL
[48]	Zhang SQ ( 2011). Tutorial of Experimental Techniques in Plant Physiology. Science Press, Beijing. 203.
	[ 张蜀秋 ( 2011). 植物生理学实验技术教程. 科学出版社, 北京. 203.]
[49]	Zhou YL, Liu QR ( 2016). Plant Biology. Higher Education Press, Beijing.
	[ 周云龙, 刘全儒 ( 2016). 植物生物学. 高等教育出版社, 北京.]
[50]	Zuo YM, Yang WZ, Yang TM, Yang MQ, Xu ZL, Yang SB, Zhang JY ( 2016). Comparison of resistant physiological index among four species in the Genus Panax under water stress. Crops, ( 3), 84-88.
	[ 左应梅, 杨维泽, 杨天梅, 杨美权, 许宗亮, 杨绍兵, 张金渝 ( 2016). 干旱胁迫下4种人参属植物抗性生理指标的比较. 作物杂志, ( 3), 84-88.]

土壤含水量(处理水平) Soil water content % FC (The level of drought)	体积含水量 Soil volumetric water content (%)	盆栽总质量(平均值±标准偏差) Pot’s mass (mean ± SD) (g)
80% FC (水分充足 Sufficient water)	28.8	13β696 ± 97
50% FC (轻度干旱 Mild drought)	18.0	12β979 ± 112
30% FC (中度干旱 Moderate drought)	10.8	12β357 ± 106
15%FC (重度干旱 Severe drought)	5.4	12β070 ± 84

土壤含水量(处理水平) Soil water content % FC (The level of drought)	体积含水量 Soil volumetric water content (%)	盆栽总质量(平均值±标准偏差) Pot’s mass (mean ± SD) (g)
80% FC (水分充足 Sufficient water)	28.8	13β696 ± 97
50% FC (轻度干旱 Mild drought)	18.0	12β979 ± 112
30% FC (中度干旱 Moderate drought)	10.8	12β357 ± 106
15%FC (重度干旱 Severe drought)	5.4	12β070 ± 84

处理 Treatment		土壤含水量 Soil moisture content
处理 Treatment		80% FC	50% FC	30% FC	15% FC	平均值 Mean
氮水平 N level	N0	3.35 ± 0.11^Cb	2.23 ± 0.25^Cc	2.60 ± 0.03^Cbc	8.33 ± 0.27^Ca	4.13 ± 2.57^C
	MN	5.77 ± 0.55^Bc	5.97 ± 0.16^Bc	12.93 ± 0.33^Bb	18.48 ± 0.18^Ba	10.79 ± 5.54^B
	HN	10.88 ± 0.09^Ac	7.43 ± 0.20^Ad	26.90 ± 1.85^Ab	37.74 ± 0.17^Aa	20.74 ± 12.83^A
平均值 Average value		6.67 ± 3.34^c	5.21 ± 2.33^d	14.14 ± 10.60^b	21.52 ± 12.94^a
F(SW×SN)		332.84^**
F(SW)		11β481.98^**
F(SN)		2β442.89^**

处理 Treatment		土壤含水量 Soil moisture content
处理 Treatment		80% FC	50% FC	30% FC	15% FC	平均值 Mean
氮水平 N level	N0	3.35 ± 0.11^Cb	2.23 ± 0.25^Cc	2.60 ± 0.03^Cbc	8.33 ± 0.27^Ca	4.13 ± 2.57^C
	MN	5.77 ± 0.55^Bc	5.97 ± 0.16^Bc	12.93 ± 0.33^Bb	18.48 ± 0.18^Ba	10.79 ± 5.54^B
	HN	10.88 ± 0.09^Ac	7.43 ± 0.20^Ad	26.90 ± 1.85^Ab	37.74 ± 0.17^Aa	20.74 ± 12.83^A
平均值 Average value		6.67 ± 3.34^c	5.21 ± 2.33^d	14.14 ± 10.60^b	21.52 ± 12.94^a
F(SW×SN)		332.84^**
F(SW)		11β481.98^**
F(SN)		2β442.89^**

处理 Treatment		土壤含水量 Soil moisture content
处理 Treatment		80% FC	50% FC	30% FC	15% FC	平均值 Mean
氮水平 N level	N0	0.516 ± 0.007^Bb	0.536 ± 0.009^Bb	0.605 ± 0.008^Aa	0.612 ± 0.010^ABa	0.568 ± 0.045^A
	MN	0.548 ± 0.005^Ab	0.564 ± 0.011^Ab	0.569 ± 0.009^Bb	0.595 ± 0.013^Ba	0.569 ± 0.020^A
	HN	0.523 ± 0.009^ABc	0.548 ±0.010 ^ABc	0.574 ± 0.008^Bb	0.633 ± 0.036^Aa	0.569 ± 0.046^A
平均值 Mean		0.529 ± 0.015^d	0.549 ± 0.015^c	0.583 ± 0.018^b	0.614 ± 0.026^a
F(SW×SN)		6.560^**
F(SW)		67.479^**
F(SN)		0.062